Category: Resolution Tests
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Testing Lenses: Best Individual Focus MTF Curves
OK, in the last post we did something useful, but rather boring: we looked at how MTF changes when lenses are stopped down. Today we’re going to use a more powerful optical bench tool, the MTF vs. Field vs. Focus. Unless you work in a metrology lab (and probably not even then, very few are…
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Testing Lenses: Stopped-Down MTF Curves
For quite a while now we’ve been publishing our MTF curves. They’ve always been the same thing; at least ten copies of each lens, in 4 rotations, and measured at the widest aperture. The reasons for that are (to us) very straightforward. Our purpose in doing the tests is to establish reasonable…
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The 8K Conundrum – When Bad Lenses Mount Good Sensors
_This is a guest post from Brandon Dube, whose name you’ve seen on many of our articles. In addition to his metrology work, he also does high fidelity numerical optical simulation, and spends his summers at places like NASA/JPL working on the cameras that are going in the Mars 2020 rover._ _This…
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The Extreme Batis: MTF Tests of the Zeiss Batis 18mm and 135mm f/2.8 Lenses
I’ve been slow to test the Batis lenses for several reasons. We can never get enough copies when they’re first released and by the time we do have enough copies I’ve got six other things to do. That said, I did give an overview of the Batis 25mm and 85mm a while back and even did a teardown of the…
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Cine Lens Comparison: 35mm Full-Frame Primes
Good day! And welcome to our first Cine lens MTF comparison. If you aren’t familiar with what we do here, I suggest you take a glance at our previous post on why we’ve started testing Cine lenses. For those of you who haven’t been here before, let’s be clear about what this is not. It is not a lens…
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Sigma 24-70mm f/2.8 DG OS HSM Art Sharpness Tests
Sigma has been on an incredible run these last 5 years, releasing one amazingly sharp lens after another. They’ve made lenses no one has ever tried before and not only succeeded, they made them amazingly good on the first try. Their quality control has become as good as anyone’s, better than most.…
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Sony FE 12-24mm f/4 G MTF Tests
*Lensrentals.com, 2017* I usually don’t do any prerelease testing. Mostly that’s because manufacturers will send one prerelease copy to a reviewer. If you tell them you won’t test less than ten copies they look at you like, well, I don’t know what they look at you like because I only communicate by…
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Sigma 135mm f/1.8 Art MTF Charts (and a Look Behind the Curtain)
I know there are a lot of people who want to see what the MTF charts on the new Sigma 135mm DG HSM f/1.8 Art lens look like. We just did our initial screening test on ten copies, so I’ll show you what we found, and give you some comparisons to some other 135mm lenses. This also presented a good…
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MTF Lens Tests of the New Tamron 70-200 f/2.8 SP Di VC USD G2
There’s been a bit of rumbling lately about the new Tamron 70-200mm f/2.8 G2 zoom. Not just because it is a frontrunner in the _2017 Most Initials in the Name Award_, but because a lot of people are saying it’s really quite good. The previous Tamron 70-200mm f/2.8 was a good lens, but since they…
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MTF Tests for the Sigma BBL: The Big, Beautiful, 85mm Art Lens
Yes, I know the Sigma 85mm f/1.4 DG HSM Art lens just too big for you; reading the online forums, you’d think it was about the same size and weight and a 600mm f/4 lens. It’s not, of course, although it is a hefty lens at nearly 40 ounces. But that’s just a few ounces more than a Canon 85mm f/1.2…
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Nikon 70-200mm f/2.8E FL ED AF-S VR MTF Tests
Well, we all want to call it the 70-200 VR III, since it replaces the Nikon 70-200 f/2.8G AF-S VR II. But the new lens is officially the 70-200mm f/2.8E FL ED AF-S VR. It is most definitely a different lens; it’s 22 elements include one fluorite, one high-refractive, and six ED elements, along with…
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Fun with Field of Focus II: Copy-to-Copy Variation and Lens Testing
I mentioned in our first post in this series that one of the major reasons I was interested in looking at field curvatures was as a means of detecting lenses that are weaker on one side (or perhaps one corner). If you haven’t looked at that post, you really need to before you tackle this one. In…
